Preoperative versus postoperative radiotherapy in soft-tissue sarcoma of the limbs: a randomised trial

Assessment of local complications with preoperative versus postoperative radiotherapy in patients with soft tissue sarcoma in extremities: A randomized comparative clinical trial

Background

Radiotherapy is considered a cornerstone as adjuvant or neo adjuvant to surgery in extremity soft tissue sarcoma (ESTS). Wound complications are the most agonizing complication that may have an impact on patient's functional outcome following radiotherapy. The best care for ESTS is by combining extensive surgical excision with safety margin and radiotherapy either preoperative (neoadjuvant) or postoperative. Preoperative radiotherapy allows for lower dose of radiation over smaller fields which is supposed to decrease long-term complications. However, several studies have shown that early complications which include wound dehiscence, infection, seroma and burn may be more frequent with preoperative radiotherapy than with postoperative radiotherapy. Most of these studies were retrospective. This study aims to prospectively assess and compare the early complications associated with radiotherapy in both techniques.

Hypothesis

Preoperative radiotherapy is not inferior to postoperative radiotherapy regarding early wound complications.

Patients and methods

Between January 2021 and June 2022, we prospectively studied 22 patients and categorized them into two groups, group A (preoperative radiotherapy) and group B (postoperative radiotherapy). We included patients with extremity soft tissue sarcoma in skeletally mature patients who were randomized into two groups with follow up 9-12 months. Wound complications, local complications, recurrence, time for wound healing and survival rate were recorded and analyzed using SPSS 25.

Results

22 patients were included, 10 in group A and 12 in group B, their mean age was 46.4 years with mean follow up 9 months. The major wound complications were higher in group A (preoperative radiotherapy). in comparison with group B (postoperative radiotherapy), however, this was not statistically significant. While other local complications were higher in group B, it was also statistically insignificant. Time for wound healing was higher in group A more than group B and was statistically significant (p value = 0.011).

Conclusion

No increase in the wound complications rate with preoperative radiotherapy by using low fractionated doses of radiotherapy and increasing interval before surgery to six weeks, although there is increased risk of delayed wound healing time after surgery. The size and site of the tumor may increase the risk of wound complications unrelated to the type of radiotherapy.

Level of evidence

II: clinical trial.

Significance of radiation therapy in the myxoid round-cell liposarcoma treatment regimen

BACKGROUND AND PURPOSE

Because myxoid liposarcomas are more radiosensitive than other soft tissue sarcomas, there have been several reports of 50 Gy preoperative radiation therapy combined with surgery, but the wound complication rate is reportedly high. We have performed preoperative irradiation at a reduced dose of 40 Gy and definitive radiation therapy for unresectable cases. This study aimed to report the tumor reduction rate and oncological results with a reduced dose of preoperative irradiation and the outcome of definitive irradiation for unresectable cases.

MATERIALS AND METHODS

Forty-one patients with myxoid liposarcoma treated in our institution between 2002 and 2021 were included. We examined the tumor volume shrinkage rate with preoperative radiation, compared complications and oncological outcomes between preoperative radiation and surgery-only cases, and investigated the prognosis and tumor shrinkage of definitive radiation cases.

RESULTS

The total dose irradiated was 40 Gy except in two cases. The mean tumor volume reduction rate was 52.0%. A decreased dose of preoperative radiation did not worsen clinical outcomes with fewer complications. The total dose of definitive radiation was approximately 60 Gy. The mean tumor volume reduction rate was 55.0%. The tumor shrinkage maintenance rate was 100% in a median follow-up period of 50.5 months.

CONCLUSION

Preoperative radiation therapy for myxoid liposarcoma near vital organs is a good approach because even with a reduced dose of 40 Gy, significant tumor reduction and excellent results were achieved. Definitive radiation therapy is the recommended treatment for older patients with serious comorbidities or inoperable patients.

Outcomes of non-angiosarcoma radiation-associated soft tissue sarcomas of the chest

BACKGROUND

Radiation-associated soft tissue sarcomas (RA-STS) are rare complications of patients receiving radiation therapy (RT) and are generally associated with a poor prognosis. Most of the literature surrounding RA-STS of the chest is centered on angiosarcoma. Therefore, we aim to document the management and outcome of patients with non-angiosarcoma RA-STS of the chest.

METHODS

We reviewed 17 patients (all female, median age 65 years) diagnosed with RA-STS. The most common primary malignancy was breast carcinoma (n = 15), with a median RT dose of 57.9 Gy. All patients underwent surgical resection; five patients (29%) received radiotherapy; and five patients (29%) received peri-operative chemotherapy.

RESULTS

The 5-year local recurrence and metastatic-free survival were 61% and 60%, while the 5-year disease-specific survival was 53%. Local recurrence was associated with death due to disease (HR 9.06, p = 0.01). Complications occurred in nine of patients, most commonly due to a wound complication (n = 7). At the most recent follow-up, the median Musculoskeletal Tumor Society Score was 63%.

CONCLUSION

RA-STS involving the chest wall are aggressive tumors with a high risk of local relapse and death due to disease. Local recurrence was associated with death due to disease; as such, we recommend aggressive surgical management with evaluation for adjuvant therapies.

Local recurrence rates of superficial versus deep soft tissue sarcoma

INTRODUCTION

Soft tissue sarcomas are a group of malignancies that commonly occur in the extremities. As deep lesions may exist within the confines of the muscular fascia, we postulate that local recurrence rates are higher for superficial soft tissue sarcomas managed by the standard of care.

MATERIALS AND METHODS

A retrospective review was performed on 90 patients who underwent surgical resection of soft tissue sarcomas of the extremity from 2007 to 2015. Patients with minimum 2-year follow-up and adequate operative, pathologic, and clinical outcomes data were included.

RESULTS

Mean age was 54 ± 18 years with 49 (54.4%) patients being male. Lesions in 77.8% of cases were deep, and 22.2% were superficial to fascia. Following the index surgical resection, a total of 33 (36.7%) patients had positive margins. A total of 17 (18.9%) patients had a local recurrence. Overall, 3-year survival was 92.7%, and 5-year survival was 79.0%. Five-year recurrence-free survival of deep sarcomas was 91.1% versus 58.2% of superficial lesions (p = 0.006). Patients with higher tumor depth had lower odds of experiencing a local recurrence (HR 0.26 [95% CI 0.09-0.72]). Local recurence rates was also associated with positive surgical margins on initial resection (33.3% versus 12.3%) (p = 0.027).

CONCLUSIONS

In this series, superficial tumor depth was associated with local recurrence of soft tissue sarcomas of the extremity following surgical resection. Positive surgical margins was also associated with local recurrence.

Outcomes for patients with head and neck sarcoma treated curatively with radiation therapy and surgery

INTRODUCTION

Soft tissue sarcomas (STS) of the head and neck (H&N) are rare malignancies that are challenging to manage. We sought to describe the outcomes of patients treated with curative intent using combined surgery and radiation therapy (RT) for H&N STS.

METHODS

We performed a single-institution retrospective review of patients with non-metastatic STS of the H&N who were treated from 1968-2020. The Kaplan-Meier method was used to estimate disease-specific survival (DSS) and local control (LC). Multivariable analyses (MVA) were conducted using Cox proportional hazards model.

RESULTS

192 pts had a median follow-up of 82 months. Tumors arose in the neck (n=50, 26%), paranasal sinuses (n=36, 19%), or face (n=23, 12%). Most patients were treated with post-operative RT (n=134, 70%). Post-op RT doses were higher (median 60Gy, pre-op 50Gy, p<0.001). Treatment sequence was not associated with LC (pre-op RT 78% (63-88), post-op RT 75% (66-82), p=0.48). On MVA, positive/uncertain margin was the only variable associated with LC (HR 2.54 (1.34-4.82), p=0.004). LC was significant on MVA (HR 4.48 (2.62-7.67), p<0.001) for DSS. Patients who received post-op RT were less likely to experience a major wound complication (MWC) (7.5% vs 22.4%, HR 0.28 (0.11-0.68), p=0.005). There was no difference in the rate of late toxicities between patients who received pre-op or post-op RT.

CONCLUSIONS

H&N STS continues to have relatively poorer LC than STS of the trunk or extremities. We found LC to be associated with DSS. Timing of RT did not impact oncologic or long-term toxicity outcomes, however pre-op RT did increase the chance of developing a MWC.

Neutrophil-to-lymphocyte ratio for the prediction of soft tissue sarcomas response to pre-operative radiation therapy

PURPOSE/OBJECTIVE

This study aims to assess the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in soft tissue sarcomas (STS) treated with pre-operative hypofractionated radiotherapy (HFRT).

MATERIALS/METHODS

This retrospective analysis included patients treated with pre-operative HFRT of 30 Gy in 5 fractions between 2016 and 2023. Clinical, demographic, and complete blood count (CBC) data were collected. NLR was calculated by dividing the absolute neutrophil count by the absolute lymphocyte count. Only patients with CBCs conducted within 6 months after radiotherapy were included. Cox proportional-hazard regression models were used to assess the impact of NLR and different variables on outcomes. Kaplan Meier were used to illustrate survival curves. A p-value < 0.05 was considered significant, and 95 % confidence intervals (CI) were employed.

RESULTS

A total of 40 patients received HFRT and had CBCs within 6 months after radiotherapy. There were 17 (42.5 %) females and 23 (57.5 %) males with a mean age of 66 years. The mean largest tumor size dimension was 7.1 cm, and the mean NLR post-RT was 5.3. The most frequent histological subtypes were myxofibrosarcoma (17.5 %), pleomorphic spindle cell sarcoma (10 %), leiomyosarcoma (7.5 %), and myxoid liposarcoma (5 %). The median follow-up period was 15.4 months. From all patients, 14 patients had disease progression, 12 metastatic disease and 3 died of disease. Multivariable Cox proportional-hazards regression analysis displayed that a higher post-RT NLR was associated with worse disease-free survival (DFS) (HR: 1.303 [1.098-1.548], p = 0.003), and distant metastasis-free survival (DMFS) (HR: 1.38 [1.115-1.710], p = 0.003). Moreover, post-NLR ≥ 4 as a single variable was associated with worse DFS, DMFS, but not worse local recurrence or overall survival.

CONCLUSION

This study is the first to evaluate NLR as a prognostic biomarker in STS patients treated with pre-operative radiotherapy. A higher NLR after pre-operative radiotherapy was associated with increased disease progression.

Natural history of undifferentiated pleomorphic sarcoma: Experience from the US Sarcoma Collaborative

BACKGROUND

Undifferentiated pleomorphic sarcoma (UPS) is a relatively rare but aggressive neoplasm. We sought to utilize a multi-institutional US cohort of sarcoma patients to examine predictors of survival and recurrence patterns after resection of UPS.

METHODS

From 2000 to 2016, patients with primary UPS undergoing curative-intent surgical resection at seven academic institutions were retrospectively reviewed. Epidemiologic and clinicopathologic factors were reviewed by site of origin. Overall survival (OS), recurrence-free survival (RFS), time-to-locoregional (TTLR), time-to-distant recurrence (TTDR), and patterns of recurrence were analyzed.

RESULTS

Of the 534 UPS patients identified, 53% were female, with a median age of 60 and median tumor size of 8.5 cm. The median OS, RFS, TTLR, and TTDR for the entire cohort were 109, 49, 86, and 46 months, respectively. There were no differences in these survival outcomes between extremity and truncal UPS. Compared with truncal, extremity UPS were more commonly amenable to R0 resection (87% vs. 75%, p = 0.017) and less commonly associated with lymph node metastasis (1% vs. 6%, p = 0.031). R0 resection and radiation treatment, but not site of origin (extremity vs. trunk) were independent predictors of OS and RFS. TTLR recurrence was shorter for UPS resected with a positive margin and for tumors not treated with radiation.

CONCLUSION

For patients with resected extremity and truncal UPS, tumor size >5 cm and positive resection margin are associated with worse survival OS and RFS, irrespectively the site of origin. R0 surgical resection and radiation treatment may help improve these survival outcomes.

Buried de-epithelialized flap: An original solution to fill dead space after sarcoma resection in the thigh. Surgical technique and results of 12 cases

INTRODUCTION

Soft tissue sarcomas (STS) are often treated with wide excision in combination with adjuvant or neoadjuvant radiotherapy. This is currently the gold standard procedure for the treatment of STS that arise in the extremities. Wound healing complications frequently occur and negatively affect the prognosis. One of the options is to use a buried de-epithelialized flap as it can increase the lymphatic flow, fill the dead space, and cover neurovascular structures and implants. This aim of this retrospective study were two-fold. 1) Describe the surgical technique for this buried de-epithelialized flap after STS removal in the thigh. 2)Evaluate the efficacy of the buried de-epithelialized flap for decreasing wound complications based on a small case series and compare it with previous publications.

HYPOTHESIS

We hypothesized that the complication rate of this flap is not higher than the published complication rate for traditional flaps.

MATERIALS AND METHODS

Twelve patients (7 women and 5 men) with a mean age of 62±12years (38-76), who underwent surgical removal of an STS in the thigh with coverage by a buried de-epithelialized flap were reviewed at a mean follow-up of 15.8months (range 8-24).

RESULTS

Two patients presented with a postoperative wound infection (17%): one superficial and one deep at the surgical site. Neither required an additional plastic surgery procedure. Another patient had a dislocation of their total hip arthroplasty that was managed by closed reduction. One patient died from metastatic progression. There was no skin necrosis of the superficial skin edges, no hematoma or seroma in the other 10 patients. The flap was still visible on cross-sectional imaging at 1 month postoperative with no fluid between the tissue planes or signs of necrosis. The rate of wound healing complications that required surgical treatment was 17% in our case series, versus 16 to 56% in previous publications reporting the results of suture closure only.

CONCLUSION

A buried de-epithelialized flap reduces the risk of skin complications by filling dead space, improving lymphatic flow and covering critical structures. It is a reliable and reproducible option after wide local excision of STS in the thigh, with no additional morbidity.

LEVEL OF EVIDENCE

IV, retrospective study.

Complications and Risk Factors in Patients with Soft Tissue Sarcoma of the Extremities Treated with Radiotherapy

INTRODUCTION

Soft tissue sarcomas of the extremities (ESTSs) pose significant challenges in treatment and management due to their diverse nature and potential complications. This study aimed to assess complications associated with multimodal treatments involving surgery and radiotherapy (RT) and to identify potential risk factors.

METHODS

We retrospectively analyzed nonmetastatic ESTS patients treated with surgery and pre- or post-operative RT between 2007 and 2020 in Strasbourg, France. Complications, including wound complications (WCs), lymphedema, acute and chronic RT-related complications, and fractures, were meticulously evaluated.

RESULTS

A total of 169 patients diagnosed with localized ESTSs were included, with a median age of 64 years (range 21-94 years). ESTSs primarily occurred proximally (74.6%) and in the lower limbs (71%). The median follow-up was 5.5 years. WCs occurred in 22.5% of patients, with proximal and lower extremity tumors being significant risk factors. Acute RT-related complications included radiodermatitis, with grade ≥ 2 occurring in 43.1% of patients, which was associated with superficial tumors. Three patients had an edema grade ≥ 2. Chronic complications included telangiectasias (21.7%) and fibrosis (38.7%), with higher rates associated with larger PTVs and higher RT doses, respectively. Fractures occurred in 5 patients, mainly in the tibia (40%).

CONCLUSIONS

Multimodal treatment of ESTSs demonstrated excellent tolerance, with manageable side effects. Numerous risk factors have been highlighted, providing insights for optimizing treatment strategies and enhancing patient care in this rare disease.

Development and benchmarking of a Deep Learning-based MRI-guided gross tumor segmentation algorithm for Radiomics analyses in extremity soft tissue sarcomas

BACKGROUND

Volume of interest (VOI) segmentation is a crucial step for Radiomics analyses and radiotherapy (RT) treatment planning. Because it can be time-consuming and subject to inter-observer variability, we developed and tested a Deep Learning-based automatic segmentation (DLBAS) algorithm to reproducibly predict the primary gross tumor as VOI for Radiomics analyses in extremity soft tissue sarcomas (STS).

METHODS

A DLBAS algorithm was trained on a cohort of 157 patients and externally tested on an independent cohort of 87 patients using contrast-enhanced MRI. Manual tumor delineations by a radiation oncologist served as ground truths (GTs). A benchmark study with 20 cases from the test cohort compared the DLBAS predictions against manual VOI segmentations of two residents (ERs) and clinical delineations of two radiation oncologists (ROs). The ROs rated DLBAS predictions regarding their direct applicability.

RESULTS

The DLBAS achieved a median dice similarity coefficient (DSC) of 0.88 against the GTs in the entire test cohort (interquartile range (IQR): 0.11) and a median DSC of 0.89 (IQR 0.07) and 0.82 (IQR 0.10) in comparison to ERs and ROs, respectively. Radiomics feature stability was high with a median intraclass correlation coefficient of 0.97, 0.95 and 0.94 for GTs, ERs, and ROs, respectively. DLBAS predictions were deemed clinically suitable by the two ROs in 35% and 20% of cases, respectively.

CONCLUSION

The results demonstrate that the DLBAS algorithm provides reproducible VOI predictions for radiomics feature extraction. Variability remains regarding direct clinical applicability of predictions for RT treatment planning.

Meta-Analysis of 5-Fraction Preoperative Radiotherapy for Soft Tissue Sarcoma

OBJECTIVES

Studies investigating preoperative 5-fraction radiation therapy (RT) for soft tissue sarcoma (STS) are limited. We performed a meta-analysis to determine the efficacy and safety of this treatment paradigm.

METHODS

This study-level meta-analysis was conducted using Bayesian methods. Statistical estimation for risk of outcome rates was conducted by posterior mean and 95% highest posterior density (HPD) intervals. Studies with 2-year local control (LC) and description of major wound complications (MWC) per the CAN-NCIC-SR2 study were included and served as the primary endpoints. Secondary endpoints included rates of acute and late toxicity. A total of 10 studies were identified and 7 met the inclusion criteria. Subgroup analyses were performed for ≥30 Gy vs <30 Gy.

RESULTS

A total of 209 patients from 7 studies were included. Five studies used ≥30 Gy (n=144), and 2 studies <30 Gy (n=64). Median follow-up was 29 months (range: 21 to 57 mo). Primary tumor location was lower extremity in 68% and upper extremity in 22%. Most tumors were intermediate or high grade (95%, 160/169), and 50% (79/158) were >10 cm. The two-year LC for the entire cohort was 96.9%, and the rate of MWC was 30.6%. There was a trend toward improved LC with ≥ 30 Gy (95% HPD: 0.95 to 0.99 vs 0.84 to 0.99). There was no difference in MWC (95% HPD: 0.18 to 0.42 vs 0.17 to 0.55) or late toxicity between the groups.

CONCLUSION

Preoperative 5-fraction RT for STS demonstrates excellent 2-year LC with MWC and toxicity similar to standard fractionation preoperative RT. Multi-institutional trials with a universal RT protocol are warranted.

Prospective phase II trial of preoperative hypofractionated proton therapy for extremity and truncal soft tissue sarcoma: the PRONTO study rationale and design

BACKGROUND

Oncologic surgical resection is the standard of care for extremity and truncal soft tissue sarcoma (STS), often accompanied by the addition of pre- or postoperative radiation therapy (RT). Preoperative RT may decrease the risk of joint stiffness and fibrosis at the cost of higher rates of wound complications. Hypofractionated, preoperative RT has been shown to provide acceptable outcomes in prospective trials. Proton beam therapy (PBT) provides the means to decrease dose to surrounding organs at risk, such as the skin, bone, soft tissues, and adjacent joint(s), and has not yet been studied in patients with extremity and truncal sarcoma.

METHODS

Our study titled "PROspective phase II trial of preoperative hypofractionated protoN therapy for extremity and Truncal soft tissue sarcOma (PRONTO)" is a non-randomized, prospective phase II trial evaluating the safety and efficacy of preoperative, hypofractionated PBT for patients with STS of the extremity and trunk planned for surgical resection. Adult patients with Eastern Cooperative Group Performance Status ≤ 2 with resectable extremity and truncal STS will be included, with the aim to accrue 40 patients. Treatment will consist of 30 Gy radiobiological equivalent of PBT in 5 fractions delivered every other day, followed by surgical resection 2-12 weeks later. The primary outcome is rate of major wound complications as defined according to the National Cancer Institute of Canada Sarcoma2 (NCIC-SR2) Multicenter Trial. Secondary objectives include rate of late grade ≥ 2 toxicity, local recurrence-free survival and distant metastasis-free survival at 1- and 2-years, functional outcomes, quality of life, and pathologic response.

DISCUSSION

PRONTO represents the first trial evaluating the use of hypofractionated PBT for STS. We aim to prove the safety and efficacy of this approach and to compare our results to historical outcomes established by previous trials. Given the low number of proton centers and limited availability, the short course of PBT may provide the opportunity to treat patients who would otherwise be limited when treating with daily RT over several weeks. We hope that this trial will lead to increased referral patterns, offer benefits towards patient convenience and clinic workflow efficiency, and provide evidence supporting the use of PBT in this setting.

TRIAL REGISTRATION

NCT05917301 (registered 23/6/2023).

UK guidelines for the management of soft tissue sarcomas

Soft tissue sarcomas (STS) are rare tumours arising in mesenchymal tissues and can occur almost anywhere in the body. Their rarity, and the heterogeneity of subtype and location, means that developing evidence-based guidelines is complicated by the limitations of the data available. This makes it more important that STS are managed by expert multidisciplinary teams, to ensure consistent and optimal treatment, recruitment to clinical trials, and the ongoing accumulation of further data and knowledge. The development of appropriate guidance, by an experienced panel referring to the evidence available, is therefore a useful foundation on which to build progress in the field. These guidelines are an update of the previous versions published in 2010 and 2016 [1, 2]. The original guidelines were drawn up by a panel of UK sarcoma specialists convened under the auspices of the British Sarcoma Group (BSG) and were intended to provide a framework for the multidisciplinary care of patients with soft tissue sarcomas. This iteration of the guidance, as well as updating the general multidisciplinary management of soft tissue sarcoma, includes specific sections relating to the management of sarcomas at defined anatomical sites: gynaecological sarcomas, retroperitoneal sarcomas, breast sarcomas, and skin sarcomas. These are generally managed collaboratively by site specific multidisciplinary teams linked to the regional sarcoma specialist team, as stipulated in the recently published sarcoma service specification [3]. In the UK, any patient with a suspected soft tissue sarcoma should be referred to a specialist regional soft tissues sarcoma service, to be managed by a specialist sarcoma multidisciplinary team. Once the diagnosis has been confirmed using appropriate imaging and a tissue biopsy, the main modality of management is usually surgical excision performed by a specialist surgeon, combined with pre- or post-operative radiotherapy for tumours at higher risk for local recurrence. Systemic anti-cancer therapy (SACT) may be utilised in cases where the histological subtype is considered more sensitive to systemic treatment. Regular follow-up is recommended to assess local control, development of metastatic disease, and any late effects of treatment.

Proton Therapy in Non-Rhabdomyosarcoma Soft Tissue Sarcomas of Children and Adolescents

This paper provides insights into the use of Proton Beam Therapy (PBT) in pediatric patients with non-rhabdomyosarcoma soft tissue sarcomas (NRSTS). NRSTS are a heterogeneous group of rare and aggressive mesenchymal extraskeletal tumors, presenting complex and challenging clinical management scenarios. The overall survival rate for patients with NRSTS is around 70%, but the outcome is strictly related to the presence of various variables, such as the histological subtype, grade of malignancy and tumor stage at diagnosis. Multimodal therapy is typically considered the preferred treatment for high-grade NRSTS. Radiotherapy plays a key role in the treatment of children and adolescents with NRSTS. However, the potential for radiation-induced side effects partially limits its use. Therefore, PBT represents a very suitable therapeutic option for these patients. The unique depth-dose characteristics of protons can be leveraged to minimize doses to healthy tissue significantly, potentially allowing for increased tumor doses and enhanced preservation of surrounding tissues. These benefits suggest that PBT may improve local control while reducing toxicity and improving quality of life. While clear evidence of therapeutic superiority of PBT over other modern photon techniques in NRSTS is still lacking-partly due to the limited data available-PBT can be an excellent treatment option for young patients with these tumors. A dedicated international comprehensive collaborative approach is essential to better define its role within the multidisciplinary management of NRSTS. Shared guidelines for PBT indications-based on the patient's age, estimated outcome, and tumor location-and centralization in high-level referral centers are needed to optimize the use of resources, since access to PBT remains a challenge due to the limited number of available proton therapy facilities.

Modern Multidisciplinary Management of Soft Tissue Sarcoma of the Extremity and Trunk

Soft tissue sarcomas (STS) of the extremity and trunk are heterogeneous and rare tumors that require coordinated multidisciplinary management. Surgical resection remains the backbone of treatment for localized tumors, with the addition of radiotherapy to surgery to achieve high rates of local control. Despite this, overall survival is limited because of significant distant metastatic risk and a lack of efficacious systemic therapies. Clinical trials have produced conflicting results on the impact of systemic therapy in the neoadjuvant and adjuvant settings for patients with localized disease, leaving systemic treatment decisions largely guided by shared decision making and prognostic prediction tools such as nomograms. This article will review the foundational data as well as latest developments in surgical, radiotherapy, and systemic management supporting current practice guidelines for localized STS of the extremity and trunk.

Update on Dosing and Fractionation for Neoadjuvant Radiotherapy for Localized Soft Tissue Sarcoma

OPINION STATEMENT

Neoadjuvant radiotherapy (RT) over 5-6 weeks with daily doses of 1.8-2.0 Gy to a total dose of 50-50.4 Gy is standard of care for localized high-grade soft tissue sarcomas (STS) of the extremities and trunk wall. One exception is myxoid liposarcomas where the phase II DOREMY trial applying a preoperative dose of 36 Gy in 2 Gy fractions (3-4 weeks treatment) has achieved excellent local control rates of 100% after a median follow-up of 25 months.Hypofractionated preoperative RT has been investigated in a number of phase II single-arm studies suggesting that daily doses of 2.75-8 Gy over 1-3 weeks can achieve similar oncological outcomes to conventional neoadjuvant RT. Prospective data with direct head-to-head comparison to conventional neoadjuvant RT investigating oncological outcomes and toxicity profiles is eagerly awaited.For the entire group of retroperitoneal sarcomas, RT is not the standard of care. The randomized multi-center STRASS trial did not find a benefit in abdominal recurrence-free survival by the addition of preoperative RT. However, for the largest histological subgroup of well-differentiated and grades I and II dedifferentiated liposarcomas, the STRASS trial and the post-hoc propensity-matched STREXIT analysis have identified a possible benefit in survival by preoperative RT. These patients deserve to be informed about the pros and cons of preoperative RT while the longer follow-up data from the STRASS trial is awaited.

Unraveling the Myth of Radiation Resistance in Soft Tissue Sarcomas

There is a misconception that sarcomas are resistant to radiotherapy. This manuscript summarizes available (pre-) clinical data on the radiosensitivity of soft tissue sarcomas. Currently, clinical practice guidelines suggest irradiating sarcomas in 1.8-2 Gy once daily fractions. Careful observation of myxoid liposarcomas patients during preoperative radiotherapy led to the discovery of this subtype's remarkable radiosensitivity. It resulted subsequently in an international prospective clinical trial demonstrating the safety of a reduced total dose, yet still delivered with conventional 1.8-2 Gy fractions. In several areas of oncology, especially for tumors of epithelial origin where radiotherapy plays a curative role, the concurrent application of systemic compounds aiming for radiosensitization has been incorporated into routine clinical practice. This approach has also been investigated in sarcomas and is summarized in this manuscript. Observing relatively low α/β ratios after preclinical cellular investigations, investigators have explored hypofractionation with daily doses ranging from 2.85-8.0 Gy per day in prospective clinical studies, and the data are presented. Finally, we summarize work with mouse models and genomic investigations to predict observed responses to radiotherapy in sarcoma patients. Taken together, these data indicate that sarcomas are not resistant to radiation therapy.

Radiotherapy versus limb-sparing surgery alone in low-grade soft-tissue sarcoma of the extremity and trunk wall: a systematic review and meta-analysis

Current guidelines recommend the use of radiotherapy in the management of intermediate and high-grade soft-tissue sarcoma of the extremity and trunk wall. Its use in low-grade sarcoma is less clear. To date there have been no pooled data analyses regarding its role in this context. Its use is not without complications and therefore must be justified. We aim to assess the oncological impact of radiotherapy versus limb-sparing surgery alone in this subset of sarcoma. Medline, EMBASE and Cochrane's databases were searched from 1982 to present. Studies on or having a subgroup analysis of low-grade soft tissue sarcoma, with a radiotherapy and a surgery only arm were included. Outcomes included local recurrence and overall survival. Patients were at least 16 years of age with primary de-novo sarcoma who had not undergone prior resection or treatment. Those undergoing concomitant therapy were excluded. Data extraction was performed independently by two reviewers. Results were pooled using a random-effects model and presented as a forest plot. Primary outcome measures included local recurrence and overall survival. Eleven unique studies were included, consisting of two RCTs and nine non-randomized studies. Overall, there were 12 799 patients. Four studies were included in meta-analysis and the overall pooled effect showed a limited role of radiotherapy in overall survival outcomes when compared to limb-sparing surgery alone HR 1.00 [0.83-1.20] P = 0.41. Descriptive analysis suggests there is limited role of radiotherapy in improving local recurrence outcomes. This study suggests there is limited role for radiotherapy versus limb-sparing surgery alone in low-grade soft-tissue sarcoma. These findings strongly suggest there is lack of high-quality data and that further research must be undertaken prior to forming any strong conclusions regarding the management of low-grade soft-tissue sarcoma. Demonstrating a role for radiotherapy may help improve the quality of excisional margins and thus potentiate limb-sparing surgery.

Well-differentiated liposarcomas and dedifferentiated liposarcomas: Systemic treatment options for two sibling neoplasms

Well-differentiated liposarcomas (WDLPS) and dedifferentiated liposarcomas (DDLPS) account for 60 % of all liposarcomas, reflecting the heterogeneity of this type of sarcoma. Genetically, both types of liposarcomas are characterized by the amplification of MDM2 and CDK4 genes, which indicates an important molecular event with diagnostic and therapeutic relevance. In both localized WDLPS and DDLPS of the retroperitoneum and the extremities, between 25 % and 30 % of patients have local or distant recurrence, even when perioperatively treated, with clear margins present. The systemic treatment of WDLPS and DDLPS remains a challenge, with anthracyclines as the gold standard for first-line treatment. Several regimens have been tested with modest results regarding their efficacy. Herein we discuss the systemic treatment options for WDLPS and DDLPS and review their reported clinical efficacy results.

Local treatment in initially unresected non-rhabdomyosarcoma soft-tissue sarcomas of children and adolescents: A retrospective single-center experience

BACKGROUND

Pediatric non-rhabdomyosarcoma soft-tissue sarcomas (NRSTS) are a heterogeneous group of aggressive tumors. Patients with locally advanced/initially unresected disease represent a subset of patients with unsatisfactory outcome: limited data are available on the best treatment approach, in particular regarding local therapy.

METHODS

This retrospective analysis concerned 71 patients < 21 years old with nonmetastatic, initially unresected adult-type NRSTS, treated at a referral center for pediatric sarcomas from 1990 to 2021. Patients were treated using a multimodal approach, based on the protocols adopted at the time of their diagnosis.

RESULTS

The series included a selected group of patients with unfavorable clinical characteristics, i.e., most cases had high-grade and large tumors, arising from axial sites in 61% of cases. All patients received neoadjuvant chemotherapy, 58 (82%) had delayed surgery (R0 in 45 cases), and 50 (70%) had radiotherapy. Partial response to chemotherapy was observed in 46% of cases. With a median follow-up of 152 months (range, 18-233), 5-year event-free survival (EFS) and overall survival (OS) were 39.9% and 56.5%, respectively. Survival was significantly better for patients who responded to chemotherapy, and those who had a delayed R0 resection. Local relapse at 5 years was 7.7% for patients who did not undergo delayed surgery.

CONCLUSIONS

Our series underscores the unsatisfactory outcome of initially unresected NRSTS patients. Improving the outcome of this patient category requires therapeutic strategies able to combine novel effective systemic therapies with a better-defined local treatment approach to offer patients the best chances to have R0 surgery.

Premastectomy Radiotherapy and Immediate Breast Reconstruction: A Randomized Clinical Trial

Importance

Premastectomy radiotherapy (PreMRT) is a new treatment sequence to avoid the adverse effects of radiotherapy on the final breast reconstruction while achieving the benefits of immediate breast reconstruction (IMBR).

Objective

To evaluate outcomes among patients who received PreMRT and regional nodal irradiation (RNI) followed by mastectomy and IMBR.

Design, Setting, and Participants

This was a phase 2 single-center randomized clinical trial conducted between August 3, 2018, and August 2, 2022, evaluating the feasibility and safety of PreMRT and RNI (including internal mammary lymph nodes). Patients with cT0-T3, N0-N3b breast cancer and a recommendation for radiotherapy were eligible.

Intervention

This trial evaluated outcomes after PreMRT followed by mastectomy and IMBR. Patients were randomized to receive either hypofractionated (40.05 Gy/15 fractions) or conventionally fractionated (50 Gy/25 fractions) RNI.

Main Outcome and Measures

The primary outcome was reconstructive failure, defined as complete autologous flap loss. Demographic, treatment, and outcomes data were collected, and associations between multiple variables and outcomes were evaluated. Analysis was performed on an intent-to-treat basis.

Results

Fifty patients were enrolled. Among 49 evaluable patients, the median age was 48 years (range, 31-72 years), and 46 patients (94%) received neoadjuvant systemic therapy. Twenty-five patients received 50 Gy in 25 fractions to the breast and 45 Gy in 25 fractions to regional nodes, and 24 patients received 40.05 Gy in 15 fractions to the breast and 37.5 Gy in 15 fractions to regional nodes, including internal mammary lymph nodes. Forty-eight patients underwent mastectomy with IMBR, at a median of 23 days (IQR, 20-28.5 days) after radiotherapy. Forty-one patients had microvascular autologous flap reconstruction, 5 underwent latissimus dorsi pedicled flap reconstruction, and 2 had tissue expander placement. There were no complete autologous flap losses, and 1 patient underwent tissue expander explantation. Eight of 48 patients (17%) had mastectomy skin flap necrosis of the treated breast, of whom 1 underwent reoperation. During follow-up (median, 29.7 months [range, 10.1-65.2 months]), there were no locoregional recurrences or distant metastasis.

Conclusions and Relevance

This randomized clinical trial found PreMRT and RNI followed by mastectomy and microvascular autologous flap IMBR to be feasible and safe. Based on these results, a larger randomized clinical trial of hypofractionated vs conventionally fractionated PreMRT has been started (NCT05774678).

Trial Registration

ClinicalTrials.gov Identifier: NCT02912312.

Extremity and Truncal Soft Tissue Sarcoma: Risk Assessment and Multidisciplinary Management

Extremity and truncal soft tissue sarcomas are a heterogeneous group of rare cancers that arise from mesenchymal tissues. Hence, the adoption of tailored risk assessment and prognostication tools plays a crucial role in optimizing the decision-making for which of the many possible treatment strategies to select. Management of these tumors requires a multidisciplinary strategy, which has seen significant development in recent decades. Surgery has emerged as the primary treatment approach, with the main goal of achieving microscopic negative tumor margins. To reduce the likelihood of local recurrence, loco-regional treatments such as radiation therapy and isolated limb perfusion are often added to the treatment regimen in combination with surgery. This approach also enables surgeons to perform limb-sparing surgery, particularly in cases where a positive tumor margin is expected. Chemotherapy may also provide a further benefit in decreasing the probability of local recurrence or reducing distant metastasis in selected patients. Selecting the optimal treatment strategy for these rare tumors is best accomplished by an experienced multi-disciplinary team.

MOF@COF Nanocapsules Enhance Soft Tissue Sarcoma Treatment: Synergistic Effects of Photodynamic Therapy and PARP Inhibition on Tumor Growth Suppression and Immune Response Activation

Soft tissue sarcomas (STS) are highly malignant tumors with limited treatment options owing to their heterogeneity and resistance to conventional therapies. Photodynamic therapy (PDT) and poly-ADP-ribose polymerase (PARP) inhibitors (PARPi) have shown potential for STS treatment, with PDT being effective for sarcomas located on the extremities and body surface and PARPi targeting defects in homologous recombination repair. To address the limitations of PDT and harness the potential of PARPi, herein, a novel therapeutic approach for STS treatment combining nanocapsules bearing integrated metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), i.e., MOF@COF, with PDT and PARPi is proposed. Nanocapsules are designed, referred to as ZTN@COF@poloxamer, which contain a Zr-based MOF and tetrakis (4-carbethoxyphenyl) porphyrin as a photosensitizer, are coated with a COF to improve the sensitizing properties, and are loaded with niraparib to inhibit DNA repair. Experiments demonstrate that this new nanocapsules treatment significantly inhibits STS growth, promotes tumor cell apoptosis, exhibits high antitumor activity with minimal side effects, activates the immune response of the tumor, and inhibits lung metastasis in vivo. Therefore, MOF@COF nanocapsules combined with PARPi offer a promising approach for STS treatment, with the potential to enhance the efficacy of PDT and prevent tumor recurrence.

Immunotherapy and Radiotherapy Combinations for Sarcoma

Sarcomas are a heterogeneous group of bone and soft tissue tumors. Survival outcomes for advanced (unresectable or metastatic) disease remain poor, so therapeutic improvements are needed. Radiotherapy plays an integral role in the neoadjuvant and adjuvant treatment of localized disease as well as in the treatment of metastatic disease. Combining radiotherapy with immunotherapy to potentiate immunotherapy has been used in a variety of cancers other than sarcoma, and there is opportunity to further investigate combining immunotherapy with radiotherapy to try to improve outcomes in sarcoma. In this review, we describe the diversity of the tumor immune microenvironments for sarcomas and describe the immunomodulatory effects of radiotherapy. We discuss studies on the timing of radiotherapy relative to immunotherapy and studies on the radiotherapy dose and fractionation regimen to be used in combination with immunotherapy. We describe the impact of radiotherapy on the tumor immune microenvironment. We review completed and ongoing clinical trials combining radiotherapy with immunotherapy for sarcoma and propose future directions for studies combining immunotherapy with radiotherapy in the treatment of sarcoma.

FLASH Radiotherapy: What Can FLASH's Ultra High Dose Rate Offer to the Treatment of Patients With Sarcoma?

FLASH is an emerging treatment paradigm in radiotherapy (RT) that utilizes ultra-high dose rates (UHDR; >40 Gy)/s) of radiation delivery. Developing advances in technology support the delivery of UHDR using electron and proton systems, as well as some ion beam units (eg, carbon ions), while methods to achieve UHDR with photons are under investigation. The major advantage of FLASH RT is its ability to increase the therapeutic index for RT by shifting the dose response curve for normal tissue toxicity to higher doses. Numerous preclinical studies have been conducted to date on FLASH RT for murine sarcomas, alongside the investigation of its effects on relevant normal tissues of skin, muscle, and bone. The tumor control achieved by FLASH RT of sarcoma models is indistinguishable from that attained by treatment with standard RT to the same total dose. FLASH's high dose rates are able to mitigate the severity or incidence of RT side effects on normal tissues as evaluated by endpoints ranging from functional sparing to histological damage. Large animal studies and clinical trials of canine patients show evidence of skin sparing by FLASH vs. standard RT, but also caution against delivery of high single doses with FLASH that exceed those safely applied with standard RT. Also, a human clinical trial has shown that FLASH RT can be delivered safely to bone metastasis. Thus, data to date support continued investigations of clinical translation of FLASH RT for the treatment of patients with sarcoma. Toward this purpose, hypofractionated irradiation schemes are being investigated for FLASH effects on sarcoma and relevant normal tissues.

Are We Ready for Life in the Fast Lane? A Critical Review of Preoperative Hypofractionated Radiotherapy for Localized Soft Tissue Sarcoma

This critical review aims to summarize the relevant published data regarding hypofractionation regimens for preoperative radiation therapy (RT) prior to surgery for soft tissue sarcoma (STS) of the extremity or superficial trunk. We identified peer-reviewed publications using a PubMed search on the MeSH headings of "soft tissue sarcoma" AND "hypofractionated radiation therapy." To obtain complication data on similar anatomical radiotherapeutic scenarios we also searched "hypofractionated radiation therapy" AND "melanoma" as well as "hypofractionated radiation therapy" AND "breast cancer." We then used reference lists from relevant articles to obtain additional pertinent publications. We also incorporated relevant abstracts presented at international sarcoma meetings and relevant clinical trials as listed on the ClinicalTrials.gov website. Detailed data are presented and contextualized for ultra-hypofractionated and moderately hypofractionated regimens with respect to local control, wound complications, and amputation rates. Comparative data are also presented for late toxicities including: fibrosis, joint limitation, edema, skin integrity, and bone fracture or necrosis. These data are compared to a standard regimen of 50 Gy in 25 daily fractions delivered over 5 weeks. This analysis supports the continued use of a standard regimen for preoperative RT for STS of 25 × 2 Gy over 5 weeks without concurrent chemotherapy. Use of concurrent chemotherapy with preoperative RT for STS should be reserved for well-designed clinical trials. A randomized trial of ultra-hypofractionated and moderately hypofractionated pre op RT for STS is warranted, but it is critical for the primary endpoint (or co-primary endpoint) to be late toxicity to: bone, soft tissue, joint, and skin.

Prognostic Factors Associated with Tumor Recurrence and Overall Survival in Soft Tissue Sarcomas of the Extremities in a Colombian Reference Cancer Center

Introduction: Soft tissue sarcomas (STS) are low-incidence tumors whose clinical and histopathological factors are associated with adverse oncological outcomes. This study evaluated prognostic factors (PF) associated with tumor recurrence and overall survival (OS) in patients diagnosed with STS of the extremities, treated at the Instituto Nacional de Cancerología (INC), Bogotá, Colombia. Materials and Methods: An analytical observational study of a historical cohort was carried out, including patients diagnosed with STS and managed surgically in the Functional Unit for Breast and Soft Tissue Tumors of the INC from January 2008 to December 2018. Results: A total of 227 patients were included; 74.5% had tumors greater than 5 cm. Most patients (29.1%) were in stage IIIB at diagnosis. Age was associated with higher mortality (HR = 1.01; CI95%: 1-1.02; p = 0.048). Tumor persistence at admission to the INC (HR = 2.34; CI95%: 1.25-4.35; p = 0.007) and histologic grade III (HR = 5.36; CI95%: 2.29-12.56; p = <0.001) showed statistical significance in the multivariate analysis for recurrence of any type, as did the PFs associated with a higher risk of local recurrence (HR = 2.85; CI95%: 1.23-6.57; p = 0.014 and HR = 6.09; CI95%: 2.03-18.2; p = 0.001), respectively. Tumor size (HR = 1.03; CI95%: 1-1.06; p = 0.015) and histologic grade III (HR = 4.53; CI95%: 1.42-14.49; p = 0.011) were associated with a higher risk of distant recurrence. Conclusions: This cohort showed that in addition to histologic grade and tumor size, tumor persistence at the time of admission has an impact on disease recurrence, so STS should be managed by a multidisciplinary team with experience in this pathology in high-volume reference centers.

Novel Postoperative Hypofractionated Accelerated Radiation Dose-Painting Approach for Soft Tissue Sarcoma

Purpose

Hypofractionated radiation therapy (RT) offers benefits in the treatment of soft tissue sarcomas (STS), including exploitation of the lower α/β, patient convenience, and cost. This study evaluates the acute toxicity of a hypofractionated accelerated RT dose-painting (HARD) approach for postoperative treatment of STS.

Methods and Materials

This is a retrospective review of 53 consecutive patients with STS who underwent resection followed by postoperative RT. Standard postoperative RT dosing for R0/R1/gross disease with sequential boost (50 Gy + 14/16/20 Gy in 32-35 fractions) were replaced with dose-painting, which adapts dose based on risk of disease burden, to 50.4 and 63, 64.4, 70 Gy in 28 fractions, respectively. The first 10 patients were replanned with a sequential boost RT approach and dosimetric indices were compared. Time-to-event outcomes, including local control, regional control, distant control, and overall survival, were estimated with Kaplan-Meier analysis.

Results

Median follow-up was 25.2 months. Most patients had high-grade (59%) STS of the extremity (63%) who underwent resection with either R1 (40%) or close (36%) margins. Four patients experienced grade 3 acute dermatitis which resolved by the 3-month follow-up visit. The 2-year local control, regional control, distant control, and overall survival were 100%, 92%, 68%, and 86%, respectively. Compared with the sequential boost plan, HARD had a significantly lower field size (total V50 Gy; P = .002), bone V50 (P = .031), and maximum skin dose (P = .008). Overall treatment time was decreased by 4 to 7 fractions, which translated to a decrease in estimated average treatment cost of $3056 (range, $2651-$4335; P < .001).

Conclusions

In addition to benefits in cost, convenience, and improved biologic effect in STS, HARD regimen offers a safe treatment approach with dosimetric advantages compared with conventional sequential boost, which may translate to improved long-term toxicity.

Development and external validation of a machine learning model for prediction of survival in undifferentiated pleomorphic sarcoma

PURPOSE

Machine learning (ML) algorithms to predict cancer survival have recently been reported for a number of sarcoma subtypes, but none have investigated undifferentiated pleomorphic sarcoma (UPS). ML is a powerful tool that has the potential to better prognosticate UPS.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of histologically confirmed undifferentiated pleomorphic sarcoma (UPS) (n = 665). Patient, tumor, and treatment characteristics were recorded, and ML models were developed to predict 1-, 3-, and 5-year survival. The best performing ML model was externally validated using an institutional cohort of UPS patients (n = 151).

RESULTS

All ML models performed best at the 1-year time point and worst at the 5-year time point. On internal validation within the SEER cohort, the best models had c-statistics of 0.67-0.69 at the 5-year time point. The Multi-Layer Perceptron Neural Network (MLP) model was the best performing model and used for external validation. Similarly, the MLP model performed best at 1-year and worst at 5-year on external validation with c-statistics of 0.85 and 0.81, respectively. The MLP model was well calibrated on external validation. The MLP model has been made publicly available at https://rachar.shinyapps.io/ups_app/ .

CONCLUSION

Machine learning models perform well for survival prediction in UPS, though this sarcoma subtype may be more difficult to prognosticate than other subtypes. Future studies are needed to further validate the machine learning approach for UPS prognostication.

A Systematic Review of the Orthoplastic Approach in Adult Lower Extremity Soft Tissue Sarcoma Flap Reconstruction

BACKGROUND

The orthoplastic approach to patient care has changed the way patients with a wide variety of lower extremity pathology are treated. Through a systematic review, we aim to analyze outcomes in adult patients with lower extremity soft tissue sarcomas who undergo an orthoplastic flap management approach to their care.

METHODS

A systematic review of adult lower extremity soft tissue sarcoma excision with plastic surgery flap reconstruction was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines searching the Pubmed, Embase, and Web of Science databases from inception to April 2023.

RESULTS

After removal of duplicates, title and abstract screening, and full-text review, 26 articles were accepted for inclusion. The total mean follow-up duration was 32.0 ± 24.3 months. Reconstruction used microvascular free flaps in 65.5% (487/743), while 34.5% (256/743) were local flaps. 85.8% (307/358) of patients ambulated postoperatively. Revision surgery was required in 21% of patients during their respective follow-up periods. The limb salvage rate was 93.4% (958/1,026). Among pooled surgical outcomes, 22.2% (225/1,012) of patients experienced a perioperative complication.

DISCUSSION

Our study demonstrates that although complication rates in lower extremity soft tissue sarcoma reconstruction may be further optimized, a multidisciplinary flap reconstructive approach provides high rates of limb salvage and functional postoperative ambulation.

Surgical Margins in Musculoskeletal Sarcoma

» Negative margin resection of musculoskeletal sarcomas is associated with reduced risk of local recurrence.» There is limited evidence to support an absolute margin width of soft tissue or bone that correlates with reduced risk of local recurrence.» Factors intrinsic to the tumor, including histologic subtype, grade, growth pattern and neurovascular involvement impact margin status and local recurrence, and should be considered when evaluating a patient's individual risk after positive margins.» Appropriate use of adjuvant therapy, critical analysis of preoperative advanced cross-sectional imaging, and the involvement of a multidisciplinary team are essential to obtain negative margins when resecting sarcomas.

Frontline and Relapsed Rhabdomyosarcoma (FAR-RMS) Clinical Trial: A Report from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG)

The Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) clinical trial is an overarching, multinational study for children and adults with rhabdomyosarcoma (RMS). The trial, developed by the European Soft Tissue Sarcoma Study Group (EpSSG), incorporates multiple different research questions within a multistage design with a focus on (i) novel regimens for poor prognostic subgroups, (ii) optimal duration of maintenance chemotherapy, and (iii) optimal use of radiotherapy for local control and widespread metastatic disease. Additional sub-studies focusing on biological risk stratification, use of imaging modalities, including [18F]FDG PET-CT and diffusion-weighted MRI imaging (DWI) as prognostic markers, and impact of therapy on quality of life are described. This paper forms part of a Special Issue on rhabdomyosarcoma and outlines the study background, rationale for randomisations and sub-studies, design, and plans for utilisation and dissemination of results.

Evaluation of the Prognostic Value of Pretherapeutic Magnetic Resonance Imaging in Predicting Soft Tissue Sarcoma Radiation Response: A Retrospective Study from a Large Institutional Sarcoma Imaging Database

Background: RT-induced hyalinization/fibrosis was recently evidenced as a significant independent predictor for complete response to neoadjuvant radiotherapy (RT) and survival in patients with soft tissue sarcoma (STS). Purpose: Non-invasive predictive markers of histologic response after neoadjuvant RT of STS are expected. Materials and Methods: From May 2010 to April 2017, patients with a diagnosis of STS who underwent neoadjuvant RT for limb STS were retrieved from a single center prospective clinical imaging database. Tumor Apparent Diffusion Coefficients (ADC) and areas under the time-intensity perfusion curve (AUC) were compared with the histologic necrosis ratio, fibrosis, and cellularity in post-surgical specimens. Results: We retrieved 29 patients. The median ADC value was 134.3 × 10-3 mm2/s. ADC values positively correlated with the post-treatment tumor necrosis ratio (p = 0.013). Median ADC values were lower in patients with less than 50% necrosis and higher in those with more than 50% (120.3 × 10-3 mm2/s and 202.0 × 10-3 mm2/s, respectively (p = 0.020). ADC values higher than 161 × 10-3 mm2/s presented a 95% sensitivity and a 55% specificity for the identification of tumors with more than 50% tumor necrosis ratio. Tumor-to-muscle AUC ratios were associated with histologic fibrosis (p = 0.036). Conclusions: ADC and perfusion AUC correlated, respectively, with radiation-induced tumor necrosis and fibrosis.

Soft Tissue Sarcomas in Adolescents and Young Adults

Soft tissue sarcomas (STS) represent a heterogeneous group of extraskeletal mesenchymal tumors that affect individuals throughout the entire age continuum. Despite this pervasive influence, key differences exist in the presentation of these sarcomas across varying age groups that have prevented a more uniform approach to management. Notably, rhabdomyosarcoma (RMS) is more common in children, while most nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) subtypes are more prevalent in adults. Older patients with NRSTS appear to have more molecularly complex biology and often present with more advanced disease compared with children. Poorer outcome disparities are observed in older patients with RMS despite receiving similar treatment as younger patients. In this review, we highlight differences in epidemiology, biology, and management paradigms for pediatric and adult patients with STS and explore opportunities for a unified approach to enhance the care and outcomes within the AYA population.

Identifying risk factors and analyzing reconstructive outcomes in patients with lower-extremity soft-tissue sarcoma

PURPOSE

Reconstructing defects after resecting soft-tissue sarcoma (STS) can be challenging. The aim of this retrospective study was to analyze the reconstructive outcomes and identify the potential risk factors in patients undergoing reconstruction after excision of lower-extremity STS.

METHODS

Patients with lower-extremity STS were included. This database was compiled of patients from a single, large National Cancer Institute-accredited academic hospital. In total, 302 patients were included between January 2016 to January 2022. Univariate and multivariate analyses were performed to calculate odds ratios (ORs) for developing complications for each patient and surgical characteristic.

RESULTS

The following factors were independent predictors of any complication: benign pulmonary disease (OR = 4.2; p = 0.02), preoperative radiotherapy (RT; OR = 2.5; p = 0.047), a tumor in the medial thigh (OR = 1.9; p = 0.03), body mass index (BMI) > 30 kg/m2 (OR = 1.05; p = 0.037), and full-thickness skin graft (OR = 5.4; p = 0.01). In the preoperative RT subgroup, reconstructing a defect via undermining and layered closure alone was an independent predictor of dehiscence (OR = 2.1; p = 0.02) and seroma (OR = 3.1; p = 0.02), whereas pedicled flaps (OR = 0.08; p = 0.001) and free flaps (OR = 0.05; p = 0.001) were independent protectors against any complication.

CONCLUSION

Information derived from this analysis will assist with accurate preoperative patient counseling, which is crucial for informed decision-making and expectation management in lower-extremity STS. BMI and pulmonary function should be optimized to the extent possible to reduce postoperative complications. Patients treated preoperatively with RT should be reconstructed with a pedicled or free flap to optimize recovery.

Case report: The first account of undifferentiated sarcoma with epithelioid features originating in the pleura

Undifferentiated epithelioid sarcoma (USEF) is a rare subtype of undifferentiated soft tissue sarcoma that presents unique challenges in clinical diagnosis and treatment. Here, we report a case of USEF occurring in the pleura of a 51-year-old man for the first time. Thoracoscopic examination revealed widespread nodular changes, and pathological analysis confirmed the presence of numerous epithelioid atypical cells. Immunohistochemical (IHC) analysis demonstrated an undifferentiated phenotype with distinct characteristics: epithelial membrane antigen (foci +), vimentin (+), Ki-67 (+70% +), TTF-1 (+), P53 (mutant type +90%), INI-1 (+), and CK5/6 (small foci +). Immunohistochemical examination of the tumor showed that the tumor was an undifferentiated epithelioid sarcoma. High-throughput DNA sequencing revealed pivotal mutations, including a nonsense mutation in the NF1 gene (c.641A > G(p.H214R)). and critical TP53 missense mutation (c.641A > G(p.H214R)). This TP53 mutation, with a tumor mutation burden of 16.5 Muts/Mb, signifies a high level of genomic instability, likely contributing to the rapid progression and aggressiveness of the disease. Detection of the TP53 mutation provides essential insights, indicating the disease's rapid progression and highlighting the potential for targeted therapies. Although the patient's disease progressed extremely rapidly and he tragically died within a week, we discussed the results of IHC and DNA sequencing in detail and discussed his possible treatment options. Insights gained from this case will be critical in shaping future diagnostic and therapeutic paradigms for USEF, particularly in the context of TP53 mutations.

The Impact of Nanomedicine on Soft Tissue Sarcoma Treated by Radiotherapy and/or Hyperthermia: A Review

This article presents a comprehensive review of nanoparticle-assisted treatment approaches for soft tissue sarcoma (STS). STS, a heterogeneous group of mesenchymal-origin tumors with aggressive behavior and low overall survival rates, necessitates the exploration of innovative therapeutic interventions. In contrast to conventional treatments like surgery, radiotherapy (RT), hyperthermia (HT), and chemotherapy, nanomedicine offers promising advancements in STS management. This review focuses on recent research in nanoparticle applications, including their role in enhancing RT and HT efficacy through improved drug delivery systems, novel radiosensitizers, and imaging agents. Reviewing the current state of nanoparticle-assisted therapies, this paper sheds light on their potential to revolutionize soft tissue sarcoma treatment and improve patient therapy outcomes.

Refusal of Adjuvant Therapies and Its Impact on Local Control and Survival in Patients with Bone and Soft Tissue Sarcomas of the Extremities and Trunk

BACKGROUND

In soft tissue or bone sarcomas, multimodal therapeutic concepts represent the standard of care. Some patients reject the therapeutic recommendations due to several reasons. The aim of this study was to assess the impact of that rejection on both prognosis and local recurrence.

METHODS

Between 2012 and 2019, a total of 828 sarcoma patients were surgically treated. Chemotherapy was scheduled as a neoadjuvant, and adjuvant multi-agent therapy was performed following recommendations from an interdisciplinary tumor board. Radiotherapy, if deemed appropriate, was administered either in a neoadjuvant or an adjuvant manner. The recommended type of therapy, patient compliance, and the reasons for refusal were documented. Follow-ups included local recurrences, diagnosis of metastatic disease, and patient mortality.

RESULTS

Radiotherapy was recommended in 407 (49%) patients. A total of 40 (10%) individuals did not receive radiation. A reduction in overall survival and local recurrence-free survival was evident in those patients who declined radiotherapy. Chemotherapy was advised for 334 (40%) patients, 250 (75%) of whom did receive all recommended cycles. A total of 25 (7%) individuals did receive a partial course while 59 (18%) did not receive any recommended chemotherapy. Overall survival and local recurrence-free survival were reduced in patients refusing chemotherapy. Overall survival was worst for the group of patients who received no chemotherapy due to medical reasons. Refusing chemotherapy for non-medical reasons was seen in 8.8% of patients, and refusal of radiotherapy for non-medical reasons was seen in 4.7% of patients.

CONCLUSIONS

Divergence from the advised treatment modalities significantly impacted overall survival and local recurrence-free survival across both treatment modalities. There is an imperative need for enhanced physician-patient communication. Reducing treatment times, as achieved with hypofractionated radiotherapy and with therapy in a high-volume sarcoma center, might also have a positive effect on complying with the treatment recommendations.

Moderate hypofractionated radiation therapy and pathologic response for soft tissue sarcomas (STS) of limbs and trunk: experience from a tertiary cancer center

BACKGROUND

Preoperative radiation therapy following by limb-sparing or conservative surgery is a standard approach for limb and trunk STS. Data supporting hypofractionated radiotherapy schedules are scarce albeit biological sensitivity of STS to radiation would justify it. We sought to evaluate the impact of moderate hypofractionation on pathologic response and its influence on oncologic outcomes.

MATERIAL AND METHODS

From October 2018 to January 2023, 18 patients with limb or trunk STS underwent preoperative radiotherapy at a median dose of 52.5 Gy (range 49.5-60 Gy) in 15 fractions of 3.5 Gy (3.3-4 Gy) with or without neoadjuvant chemotherapy. A favorable pathologic response (fPR) was considered as ≥ 90% tumor necrosis on specimen examination.

RESULTS

All patients completed planned preoperative radiotherapy. Eleven patients (61.1%) achieved a fPR, and 7 patients (36.8%) a complete pathologic response with total disappearance of tumor cells. Nine patients (47%) developed grade 1-2 acute skin toxicity, and 7 patients (38.8%) had wound complications on follow-up. With a median follow-up of 14 months (range 1-40), no cases of local relapse were observed, and actuarial 3-year overall survival (OS) and distant metastases-free survival (DMFS) are 87% and 76.4%, respectively. In the univariate analysis, the presence of a favorable pathologic response (fPR) was associated with improved 3-year OS (100% vs. 56.03%, p = 0.058) and 3-year DMFS (86.91% vs. 31.46%, p = 0.002). Moreover, both complete or partial RECIST response and radiological stabilization of the tumor lesion showed a significant association with higher rates of 3-year distant metastasis-free survival (DMFS) (83% vs. 83% vs. 56%, p < 0.001) and 3-year overall survival (OS) (100% vs. 80% vs. 0, p = 0.002).

CONCLUSIONS

Preoperative moderate hypofractionated radiation treatment for STS is feasible and well tolerated and associates encouraging rates of pathologic response that could have a favorable impact on final outcomes.

A Pilot Study of Pembrolizumab Combined With Stereotactic Ablative Radiotherapy for Patients With Advanced or Metastatic Sarcoma

OBJECTIVES

Immunotherapy with immune checkpoint inhibitors has shown only limited success in the management of metastatic soft tissue sarcoma. Overall response rates (ORR) with single agent pembrolizumab were 18% and median PFS was 18 weeks on the clinical trial SARC028. One strategy to improve the responses to immunotherapy is with stereotactic body radiation therapy (SBRT), which can enhance the antitumor CD8 T cell response through the release of tumor-specific antigens, potentially priming a more diverse class of T cell receptors.

METHODS

This is a phase 0, pilot prospective study taking place at a single center with 2 arms. In Arm A, patients are treated with pembrolizumab 400 mg IV infusion on day 1 of a 42-day cycle. Stereotactic body radiation therapy (SBRT) is delivered in 1-5 fractions starting on C1D15-28 and given every other day. In Arm B, patients who have started an immune checkpoint inhibitor within 60 days are treated with SBRT in addition to the current therapy.

RESULTS

In this study we outline testing the feasibility of adding SBRT to pembrolizumab.

CONCLUSION

The ultimate goal of combination therapy is improved overall response, including tumors not treated with SBRT. This trial can be found registered online: NCT05488366.

2023 Radiation oncology highlights

Radiation oncology plays an important role in the local treatment of cancers. Understanding recent advances in the application of radiation therapy to solid tumors is important for all disciplines. The radiation oncology section editors for this journal have selected the following articles for their overall significance, relevance to surgical oncologists, and to illustrate important concepts within the practice of radiation oncology.

Meta-analysis of 5-day preoperative radiotherapy for soft tissue sarcoma (5D-PREORTS)

BACKGROUND AND PURPOSE

Although the role of conventionally fractionated radiotherapy (RT) in combination with surgery in the limb-sparing treatment of soft tissue sarcoma (STS) patients is well established, the effectiveness and safety of 5-day preoperative radiotherapy (RT) remain controversial. We performed a meta-analysis to evaluate the treatment outcomes of 5-day preoperative RT using ≥ 5 Gy per fraction with contemporary radiotherapy techniques.

MATERIALS AND METHODS

Medline, Embase, the Cochrane Library, and the proceedings of annual meetings through March 2022 were used to identify eligible studies. Following the PRISMA and MOOSE guidelines, a meta-regression analysis was performed to assess possible correlations between variables and outcomes. A p-value < 0.05 was considered significant.

RESULTS

Nine prospective studies with 786 patients (median follow-up 35 months, 20-60 months) treated with preoperative RT delivered a median total of 30 Gy (25-40 Gy) in 5 fractions. The local control (LC), R0 margins, overall survival (OS), and distant relapse (DR) rates were 92.3% (95% CI: 87---97%), 84.5% (95% CI: 78---90%), 78% (95% CI: 70---86%), and 36% (95% CI: 70---86%). The meta-regression analysis identified a significant relationship between biological equivalent dose (BED) and larger tumor size for LC and R0 margins (p < 0.05). The subgroup analysis reveals that patients receiving BED ≥ 90 (equivalent to 30 Gy in 5 fractions) had a higher LC control rate than BED < 90 (p < 0.0001). The complete pathologic response and amputation rates were 19% (95% CI: 13-26%) and 8.3% (95% CI: 0.5-15%). Amputation rates were higher in studies using the lowest and highest doses and were related to salvage surgery after recurrence and complications, respectively. The rate of wound complication and fibrosis grade 2 or worse was 30% (95% CI 23-38%) and 6.4% (95% CI 1.9-11%).

CONCLUSION

A 5-day course of preoperative RT results in high LC and favorable R0 margins, with acceptable complication rates in most studies. Better local control and R0 margins were associated with regimens using higher BED, i.e., doses equal to or higher than 30 Gy when using 5 fractions.

Emerging innovations and advancements in the treatment of extremity and truncal soft tissue sarcomas

In this special edition update on soft tissue sarcomas (STS), we cover classifications, emerging technologies, prognostic tools, radiation schemas, and treatment disparities in extremity and truncal STS. We discuss the importance of enhancing local control and reducing complications, including the role of innovative imaging, surgical guidance, and hypofractionated radiation. We review advancements in systemic and immunotherapeutic treatments and introduce disparities seen in this vulnerable population that must be considered to improve overall patient care.

What is the optimal (neo)adjuvant strategy of extremity high-risk soft tissue sarcomas (ESTS)?

Currently, the standard treatment for extremity high-risk soft tissue sarcomas (ESTS) combines surgery and pre- or post-op radiation therapy (RT). In some selected cases, chemotherapy (CT) is incorporated into the therapeutic algorithm as a neoadjuvant approach to enable conservative management. Given the risk of local or metastatic relapse, this paper discusses the potential benefits of CT and RT in high-grade ESTs. The role of adjuvant chemotherapy in addition to neoadjuvant CT, the prognostic value of the pathological response to neoadjuvant treatment, and the role for an adjuvant "boost" following resection after pre-operative radiotherapy will be discussed.

Comparison of pre-operative and post-operative radiotherapy in patients with localized myxoid liposarcoma

BACKGROUND

Myxoid liposarcoma is more radiosensitive than other soft tissue sarcomas, and radiotherapy has been reported to reduce tumour size. This study was performed to compare the rates of local recurrence, survival and wound complications between pre- and post-operative radiotherapy for localized myxoid liposarcoma.

METHODS

From the Japanese Nationwide Bone and Soft Tissue Tumor Registry database, 200 patients with localized myxoid liposarcoma who received pre- (range, 30-56 Gy) or post-operative (range, 45-70 Gy) radiotherapy and surgery were included in this retrospective study. Propensity score matching was used to adjust for background differences between patients who received pre- and post-operative radiotherapy.

RESULTS

Local recurrence occurred in five (5.0%) and nine (9.0%) patients in the pre- and post-operative radiotherapy groups, respectively (both n = 100). The median follow-up time from diagnosis was 40.5 months (IQR, 26.3-74). Univariate analysis showed a similar risk of local recurrence between the pre- and post-operative radiotherapy groups (5-year local recurrence-free survival 94.9% [95% CI 87.0-98.1] vs. 89.0% [95% CI 79.6-94.3]; P = 0.167). Disease-specific survival was similar between the pre- and post-operative radiotherapy groups (5-year disease-specific survival 88.1% [95% CI 75.5-94.6] vs. 88.4% [95% CI 77.3-94.5]; P = 0.900). The incidence of wound complications was similar between the pre- and post-operative radiotherapy groups (7.0% vs. 12.0%; P = 0.228).

CONCLUSIONS

There was no difference in local recurrence, survival or incidence of wound complications between pre- and post-operative radiotherapy for localized myxoid liposarcoma. Therefore, pre-operative radiotherapy for myxoid liposarcoma provides clinical results equivalent to post-operative radiotherapy.

The health-related quality of life of sarcoma patients treated with neoadjuvant versus adjuvant radiotherapy - Results of a multi-center observational study

AIM

The sequence of radiotherapy and resection in patients with soft tissue sarcomas is usually discussed on an individual basis. Better understanding of potential differences of health-related quality of life (QoL) between patients undergoing adjuvant (ART) versus neoadjuvant radiotherapy (NART) is therefore helpful for clinical decision making.

METHODS

Adult sarcoma patients from 39 hospitals completed the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC QLQ-C30). Differences in global QoL, physical functioning, role functioning, fatigue, pain, and insomnia between ART versus NART were investigated with multivariate regression, adjusting for age, gender, chemotherapy, grading, stage, tumor location, recurrence/distant metastasis, sarcoma type, time since last treatment, and treatment status using validated thresholds.

RESULTS

A total of 1110 patients participated. Of them, 340 had received radiotherapy (NART: n = 95, 28%; ART: n = 245, 72%). Global QoL was 59.3 on average after NART and 60.5 after ART (Badj = 1.0, p = 0.74). Physical functioning was 65.9 compared to 70.5 (Badj = 4.2; p = 0.16), role function 48.8 vs. 56.7 (Badj = 7.0, p = 0.08), fatigue 47.5 vs. 45.4 (Badj = -1.2; p = 0.71), pain 40.2 vs. 34.1 (Badj = -6.8; p = 0.08), and insomnia 33.7 vs. 41.6 (Badj = 5.5, p = 0.16). Among patients with NART, clinically relevant QoL impairments were less frequent 2 years after treatment compared to < 2 years thereafter (n = 6 vs. n = 4 on average).

CONCLUSION

There is little evidence for QoL differences in most domains and overall QoL between the two irradiation groups. However, patients after NART might experience worse role functioning and pain but fewer problems with insomnia compared to patients after ART.

Effect of radiotherapy on local recurrence, distant metastasis and overall survival in 1200 extremity soft tissue sarcoma patients. Retrospective analysis using IPTW-adjusted models

BACKGROUND AND PURPOSE

Neoadjuvant (NRTX) and adjuvant radiotherapy (ARTX) reduce local recurrence (LR) risk in extremity soft tissue sarcoma (eSTS), yet their impact on distant metastasis (DM) and overall survival (OS) is less well defined. This study aimed at analysing the influence of NRTX/ARTX on all three endpoints using a retrospective, multicentre eSTS cohort.

MATERIALS AND METHODS

1200 patients (mean age: 60.7 ± 16.8 years; 44.4 % females) were retrospectively included, treated with limb sparing surgery and curative intent for localised, high grade (G2/3) eSTS. 194 (16.2 %), 790 (65.8 %), and 216 (18.0 %) patients had received NRTX, ARTX and no RTX, respectively. For the resulting three groups (no RTX vs. NRTX, no RTX vs. ARTX, NRTX vs. ARTX) Fine&Gray models for LR and DM, and Cox-regression models for OS were calculated, with IPTW-modelling adjusting for imbalances between groups.

RESULTS

In the IPTW-adjusted analysis, NRTX was associated with lower LR-risk in comparison to no RTX (SHR [subhazard ratio]: 0.236; p = 0.003), whilst no impact on DM-risk (p = 0.576) or OS (p = 1.000) was found. IPTW-weighted analysis for no RTX vs. ARTX revealed a significant positive association between ARTX and lower LR-risk (SHR: 0.479, p = 0.003), but again no impact on DM-risk (p = 0.363) or OS (p = 0.534). IPTW-weighted model for NRTX vs. ARTX showed significantly lower LR-risk for NRTX (SHR for ARTX: 3.433; p = 0.003) but no difference regarding DM-risk (p = 1.000) or OS (p = 0.639).

CONCLUSION

NRTX and ARTX are associated with lower LR-risk, but do not seem to affect DM-risk or OS. NRTX may be favoured over ARTX as our results indicate better local control rates.

Clinical characteristics of sarcoma patients: a population-based data analysis from a German clinical cancer registry

PURPOSE

Sarcomas are a heterogeneous group of malignant neoplasms with a wide range of histological types and occur in almost any anatomic site and side. This study evaluated the prognostic factors in sarcoma patients based on German clinical cancer registry data.

METHODS

The German clinical cancer register of Saxony-Anhalt was used for all data analyses. Sarcoma cases of all clinical or pathological T-stages (T1a-T4c), all N-stages (N0-3) and M-stages (0-1b) corresponding to the Union for International Cancer Control (UICC) stages I to IVB were considered. In our analyses, 787 cases diagnosed between 2005 and 2022 were included. Further, we assessed the association of cancer-related parameters with mortality and hazard ratios (HR) from the Cox proportional hazard models. We included sex, age at diagnosis, histological grade, T-, N- and M-stages, tumor size, tumor localization and tumor side as parameters in our regression models.

RESULTS

The majority of sarcoma patients were diagnosed with leiomyosarcoma (12%), liposarcoma (11%), angiosarcoma (5.3%) and myxofibrosarcoma (2.7%). In our univariate regression models, tumors localized in more than one location, head, face and neck region as well as the pelvis and lower extremity were associated with increased mortality risk (more than one location: HR 7.10, 95% CI 2.20-22.9; head, face and neck: HR 1.35, 95% CI 0.89-2.06; pelvis: HR 1.27, 95% CI 0.86-1.89; lower extremity: HR 1.44, 95% CI 1.05-1.96). Higher histological grades, UICC-grades and TNM-stages were related to a higher mortality risk. Differing histological subtypes had significant influence on overall survival and progression-free survival. Patients diagnosed with fibromyxoid sarcoma, rhabdomyosarcoma and angiosarcoma were related to higher mortality risk compared to other histological subtypes (fibromyxoid sarcoma: HR 5.2, 95% CI 0.71-38.1; rhabdomyosarcoma: HR 2.93, 95% CI 1.44-6.00; angiosarcoma: HR 1.07, 95% CI 0.53-2.18).

CONCLUSIONS

Histological grade, tumor size, nodal and distant metastasis, tumor localization and histological subtype were determined as prognostic factors in terms of survival.